German boxing legend Dariusz 'Tiger' Michalczewski has warned Arthur Abraham (33-3, 27 KOs) to stay focused on Saturday night in Kiel. The WBO's European super middleweight champion will defend his title at 168-pounds against former EBU king Piotr Wilczewski (30-2, 10 KOs). Michalczewski consider the Polish fighter to be a very good boxer, and those kind of fighters present the most problems for Abraham.